Exotic mushroom species being cultivated in Gisborne

Enrique Perez with a sample of the oyster mushrooms he is growing in shipping containers. The mushrooms are shaped like oysters and have a flavour resemblance to the delicacy. Pictures by Liam Clayton

Pods packed with pasteurised straw and suspended from a shipping container ceiling produce an exotic mushroom species being cultivated in Gisborne.

In two containers tucked in a corner in the Industrial Subdivision, Mexican agronomist Enrique Perez produces about 40 kilograms a week worth of fan-shaped fungi known as oyster mushrooms.

In the wild, the flavoursome mushrooms do not grow in the field but on rotted wood in the forest.

“I thought ‘what could I grow without much land’ and mushrooms popped up,” says Mr Perez.

“Our business name Del Bosque means ‘from the forest’. We replicate forest conditions in a controlled environment.”

The name of the pink and white clusters, commonly known as oyster mushrooms, refer to the shape of the fruiting body.

The Latin term Pleurotus pulmonarius refers to the sideways growth of the stem while the shape of the cap resembles that of the oyster. Many people believe the name is fitting because of a flavour resemblance to the oyster.

In one laboratory container, oyster mushroom spores are germinated in a concoction of instant potato and a jelly-like substance called agar. Once the spores germinate into mycelium, they are mixed with wheat grain.

“The mycelium then feeds on the grain. Then we break up the grain and mix it with pasteurised straw. You break up the mycelium, then it becomes one again because it’s the same organism.”

The inoculated straw is stuffed into clear plastic bags and holes are punched in the bags. The mushrooms grow in clusters sideways out of the holes.

“The mycelium is spread throughout the bag. It senses where to grow out. You control the size of the clusters by the number of holes in the bag. If you scaled up production to a hectare we would produce 700 tonnes per hectare a year.”

By comparison, silage produces about 50 tonnes a hectare a season while maize produces about 15 tonnes over six months.

Oyster mushrooms take 13 weeks to mature from germination and are best used fresh. Their texture is different from that of field mushrooms and button mushrooms.

Mr Perez’s favourite oyster mushroom dishes are stir fry and rice risotto. He also recommends frying them in garlic and butter.

Mr Perez was the winner of the Young Grower award at fruit marketing company First Fresh’s inaugural awards in 2016.

His main outlet for oyster mushrooms is the Farmers’ Market.

He looks forward to approval from the Ministry for Primary Industries so he can supply restaurants with the delicacy.